The purpose of this study was to examine colorfastness of naturally-dyed fabrics using contact dyeing and a natural mordant in relation to different mordant concentrations, mordanting procedures, and heating times. Natural dyes still are exclusively used with chemical mordants and large quantities of water, making the process of natural dyeing unsustainable. The use of the contact dyeing method and natural mordant may have potential for reducing water wastes and developing a more sustainable way of natural dying. Mashed blue berries were sprayed on bleached cotton fabrics, and vinegar, used as a mordant, was applied in different mordant concentrations, mordanting procedures, and times exposed to heat. Results indicate time exposed to heat had significant impact on color change and staining on cotton rather than mordant concentrations and mordanting procedures. Further research is needed because overall colorfastness of the contact-dyed cotton fabrics to laundering was poor to moderate